Simple Interest
Math MCQs

Question :    What amount does Jessica have to pay after 6 years if he takes a loan of $3750 at 3% simple interest?

Correct Answer  $4425

Solution & Explanation

Solution

Given,

Principal (P) = $3750

Rate of Simple Interest (SI) = 3%

Time (t) = 6 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3750 × 3% × 6

= $3750 ׳/₁₀₀ × 6

= ^{3750 × 3 × 6}/₁₀₀

= ^{11250 × 6}/₁₀₀

= ⁶⁷⁵⁰⁰/₁₀₀

= $675

Thus, Simple Interest = $675

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3750 + $675

= $4425

Thus, Amount to be paid = $4425 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3750

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 6 years

Thus, Amount (A)

= $3750 + ($3750 × 3% × 6)

= $3750 + ($3750 ׳/₁₀₀ × 6)

= $3750 + (^{3750 × 3 × 6}/₁₀₀)

= $3750 + (^{11250 × 6}/₁₀₀)

= $3750 + (⁶⁷⁵⁰⁰/₁₀₀)

= $3750 + $675 = $4425

Thus, Amount (A) to be paid = $4425 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $3750, the simple interest in 1 year

= ³/₁₀₀ × 3750

= ^{3 × 3750}/₁₀₀

= ¹¹²⁵⁰/₁₀₀ = $112.5

Thus, simple interest for 1 year = $112.5

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $112.5 × 6 = $675

Thus, Simple Interest (SI) = $675

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3750 + $675

= $4425

Thus, Amount to be paid = $4425 Answer

Similar Questions

(1) Richard took a loan of $5200 at the rate of 10% simple interest per annum. If he paid an amount of $8840 to clear the loan, then find the time period of the loan.

(2) Matthew took a loan of $6400 at the rate of 7% simple interest per annum. If he paid an amount of $9536 to clear the loan, then find the time period of the loan.

(3) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $8424 to clear the loan, then find the time period of the loan.

(4) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 6% simple interest?

(5) How much loan did William borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6600 to clear it?

(6) What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 6% simple interest?

(7) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 6% simple interest?

(8) Richard took a loan of $5200 at the rate of 7% simple interest per annum. If he paid an amount of $7384 to clear the loan, then find the time period of the loan.

(9) How much loan did Deborah borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8940 to clear it?

(10) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 2% simple interest.